Combine & Compress (css, js)
According to Yahoo!'s Exceptional Performance Team, 40% to 60% of Yahoo!'s users have an empty cache experience and about 20% of all page views are done with an empty cache (see this article by Tenni Theurer on the YUIBlog for more information on browser cache usage).
News 2013-07-23 Minify 2.1.7 is released in response to a serious vulnerability discovered in all previous versions. You are strongly urged to follow the instructions in the report to secure your installation, and to upgrade to Minify 2.1.7.
Closure Compiler - Компресия на кода